Transmitter tube for ultra-short waves



Aug. 8, 1933.

F. SCHROTER 1,640

TRANSMITTER TUBE FOR ULTRA-SHORT WAVES Filed March 9, 1933' INVENTOR- FRITZ SCHROETER umrso srA'ras Patented Aug. 8, 1933 PATENTIQFZFICE" TRANSMITTER TUBE roa ULTRA-SHOE waves 7 Fritz Schriiter, Berlin, Germany, assignor to .Telefunken vGesellschaft fiir Drahtlose Telegraphic in. b. H., Berlin, Germany, aCorpora- 'tion of Germany Application March 9, 1933, Serial No. 660,144, and in Germany December 29, 1931 4 Claims. (01. 179-171 resultant or generated waves or oscillations is V In the generation of extremely short waves, especially those of an order of one decimeter by the use of the Barkhausen-Kurz circuit scheme wherein there is impressed on the grid of a tube 5 a high positive potential and to the anode a low negative or low positive potential in referenceto the filament, it is necessary to choose the loss energy which a tube may be expected to sustain, as high as possible. In the, case of a Barkhausen- Kurz tube certain problems, especially of athermal nature, different from those in standard or a conventional tubes are found to arise,, In the) latter types it is only the anode or plate that carries a thermic load inasmuch as it carries almost exclusively the entire emission current, and'since it operates at high potentials in reference to the cathode or filament. In the Barkhausen-Kurz circuit arrangement, however, only the grid carries a thermal load, whereas the plate is free from pecially inthe Barkhausen-Kurz circuit scheme, is facilitated and a substantial progress in the de- 35., sign and construction of such tubes is obtained. The invention more particularly consists in that the grid, by ways and means known in the earlier art of tubes, is rendered black or rough super- I ficially by suitable treatment, with a view to make 40" the same especially efllcient for thermal radiation, while at the same time the plate surrounding the grid has the form of an apertured hollow body, preferably of the shape of a wire network or gauze. In this way, conditions are made so that higher current load of the grid can be combined with limited electrode area or surface without incidentally endangering the plate by marked heat radiation. In addition to the fact that the yieldedpower can be increased, the said scheme offers this further merit that the length of the' material.

reduced owing to the reduction in the capacity. The substance employed for blackening the grid could be used at the same time as a getter. 'For this purpose'zirconium has been found to be eminently suited. i v A transmitting circuit'which may be usedwith the present invention is shown in the single accompanying drawing wherein there is shown means for transmitting modulated telegraph signals over a Barkhausenj-Kurzcircuit by means of a-key. In the drawing is shown a Barkhausen- I Kurz tube 1 whose grid is blackened and/or roughened for thermal radiationpurposes, and whose plate comprises'a perforated gauze-like Suitable sources of potential 2 and 3 supply the grid andanode with high positive and 3 low negative potentials, respectively, as shown.

The modulated oscillations produced by the op-:

eration of telegraph key 4 are transmitted over a bi-polar antenna 5, the positive grid potential being prevented from entering the antenna and parallel leads extending from the tube thereto by blocking condenser 6. It will be understood; of

course, that telephonic modulating'means may-be substituted for telegraph key 4 if desired.

I claim: Y v a 1. An ultra short wave oscillation generator comprising an electron discharge device having a 'cathode, anode and control electrode, means for applying a high positive potential to said control electrode, and a much lower potential to said anode relative tosaid cathode, the surface of said control electrode being blackened for aiding thermal radiation and said anode being perforated whereby there is obtained a reduction in capacity between said anode and control electrode. I

2. An ultra short wave oscillation generator comprising an electron discharge device having a cathode, anode and control electrode, meansfor applying a high positive potential to, said control electrode, and .amuch lower potential-to said anode relative to said cathode, the surface of said j control electrode being blackened and roughened for aiding thermal radiation and said anode being perforated whereby there is obtained a-reduction in capacity between saidanode and control electrode.

3. An ultra short wave oscillation generator comprising an electron discharge device having a cathode, anode and control electrode, means for applying a high positive potential to said control electrode and a much lower potential to said anode relative to said cathode, the surface of said control electrode being treated for aiding ther- 'mal radiation and said anode being perforated whereby there is obtained a reduction in capacity between said anode and control electrode.

4. Anultra short wave communication circuit for transmitting modulated oscillations of the order of a meter and less, comprising an electron discharge device having a cathode, anode and control electrode, means for applying a high posisage to be transmitted. I

FRITZ SCHROTER. 

